How To Create FTP Users Outside of Cpanel

Hello my site calls for being able to create individual FTP users automatically when someone registers, I am trying to do it through Sudo but cPanel is restricting me from being able to add an FTP user except manually through the control panel. Is there anything I can do so that I can add these FTP users directly as part of the sign up process of my site? Thank you sooo much for any help you can give!!!